: When I run my washing machine, which is next to a toilet, during the drain cycles the toilet bubbles, but does not stink, I live in an old house country home with a tank and field. The field is boarderline failing(occassionally the septic tank top releases some gray water. is this a vent problems, a septic problem or something else. I also get some noise out of the sink in the same room, but no smell.ED: Sounds like the holding tank to the field is patially plugged.( First,check the roof vent to make sure it's clear)If vents are clear,then probably the "solids" are clogging the entrance/exit in the holding tank. The release of grey/black water is the tip-off, best to get it serviced or you will end up getting the SMELL, sooner than you think. Good luck..Hube